PRODUCT DATA

® U.S. Registered TrademarkCopyright © 2003 Honeywell International Inc. All Rights Reserved 60-2150-12

L404A-D, F; L604A,LPressuretrol® Controllers

APPLICATIONL404 and L604 Pressuretrol® Controllers are line voltage pressure controllers that provide operating control, automatic limit protection, or manual reset limit protection for pressure systems of up to 300 psi (21.1 kg/cm2 or 2068 kPa).

FEATURES� Can be used with steam, air, non-combustible gases,

or fluids non-corrosive to the pressure sensing element.

� Stainless steel diaphragm (except 300 psi [21.1 kg/cm2; 2068 kPa] models) also allows use with ammonia, oxygen, distilled water and similar media.

� L404B is recommended for supervision of atomizing medium pressure in oil burner systems.

� Models are available with single-pole, single-throw (spst), single-pole, double-throw (spdt), or double-pole single-throw (dpst) switching and in a variety of operating ranges.

� Dustproof, trouble-free mercury switches (all models except L404F, which has snap-acting switch).

� Automatic reset models have adjustable, subtractive differential.

� Trip-free mechanism on manual reset models assures that limit function of controller cannot be defeated by jamming reset lever.

� Screw adjustments made on top of case.� Scaleplates marked in English (psi) and Metric

(kg/cm2) units.� L404F models available with European enclosure,

British Standard Pipe Threads, ground screw, and scale plates marked in kg/cm2 and either psi or kPa.

� Clear plastic cover on case to observe pressure settings and switch action.

� Leveling indicator visible through cover.� Hexagonal fitting with 1/4-18 NPT internal threads for

direct mounting to 14026 Steam Trap (siphon loop).� Surface mount is available using screws through holes

(knockouts) in case backing.

ContentsApplication ........................................................................ 1Features ........................................................................... 1Specifications ................................................................... 2Ordering Information ........................................................ 2Installation ........................................................................ 5Setting and Checkout ....................................................... 8Service Information .......................................................... 10

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

60-2150�12 2

ORDERING INFORMATIONWhen purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the TRADELINE® Catalog or price sheets for complete ordering number.

If you have additional questions, need further information, or would like to comment on our products or services, please write or phone:

1. Your local Honeywell Automation and Control Products Sales Office (check white pages of your phone directory).2. Honeywell Customer Care

1885 Douglas Drive NorthMinneapolis, Minnesota 55422-4386

In Canada�Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Scarborough, Ontario M1V 4Z9.International Sales and Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France, Germany, Japan, Mexico, Netherlands, Spain, Taiwan, United Kingdom, U.S.A.

SPECIFICATIONS

TRADELINE® ModelsTRADELINE® models are selected and packaged to provide ease of stocking, ease of handling and maximum replacement value. Specifications of TRADELINE® controls are the same as those of standard models, except as noted below.

TRADELINE® Models Available:L604A Pressuretrol® Controllers�available in 2 to 15, 5 to

50, 10 to 150 and 20 to 300 psi (0.14 to 1.1 kg/cm2 [14 to 103 kPa], 0.4 to 3.5 kg/cm2 [34 to 345 kPa], 0.7 to 10.6 kg/cm2 [69 to 1034 kPa], and 1.4 to 21.0 kg/cm2 [138 to 2068 kPa]).

Additional Features: TRADELINE® pack with cross-reference label.

Standard Models:Models:

L404A-D,F and L604A,L Pressuretrol® Controllers. See Table 1.

NOTE: A 14026 Steam Trap (siphon loop) is available, except where noted in Table 1. The steam trap is necessary for boiler installations.

Switches: Mercury switches in all models except the L404F which

has a Micro Switch� snap-acting switch.Pressure Sensing Element:

Stainless steel diaphragm (brass bellows in 300 psi [21.1 kg/cm2 (2068 kPa)] models).

Ambient Temperature Range:-35°F (-37°C) to +150°F (66°C).

NOTE: Also, see the NOTE in the Location and Mounting section.

Adjustment Means:Screws on top of controller case. Scales are marked in psi

and kPa.Electrical Connections:

Internal screw terminals; hole in side of case for 1/2 in. (13 mm) conduit.

Mounting:Hexagonal fitting on diaphragm has 1/4-18 NPT internal

threads for mounting on a pipe or steam trap (siphon loop). Also can be surface-mounted using screws through two holes (knockouts) in back of case.

Dimensions: See Fig. 1. See Fig. 2 for mounting steam trap (siphon loop).

Weight: 2 lb. (0.91 kg).

Finish: Gray.

Approvals:Underwriters Laboratories Inc. Listed (L404A,B,C,D,F; L604A,L only); file no. MP466, vol. 10, guide no. MBPR.

Canadian Standards Association certified (L404A,B,C,D,F; L604A,L only); file no. LR1620; guide no. 400-E-0.

Replacement Parts:129178 Thermoplastic Cover.14026 Steam Trap (siphon loop)�1/4 in. black iron pipe;

necessary for boiler installations.

Accessories:33312B Knurled Adjustment Knob�with setscrew; fits on

main scale pressure adjusting screw.4074BWJ Limit Stop Assembly�to limit setpoint ranges;

includes 129564 Range Stop, 107194 Range Stop Screw, and 23466 Wrench.

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

3 60-2150�12

a Scaleplates are marked in both psi and kg/cm2.b L404A,B and L604A models are available with 1 to 6 psi midscale subtractive differential in 2 to 15 psi models.c Brass bellows replace stainless steel diaphragm. Not suitable for use with ammonia, oxygen, or other corrosive materials.d L404C,D and L604L models are designated as Manual Reset 2 controllers; the trip-free reset mechanism does not permit the

controller to function as an automatic-reset device when the manual reset lever is held in the reset position. The subtractive differential is fixed at the minimum value of the adjustable differential of the L404A for each corresponding operating range.

e L404F only; all other models have mercury switches.f Also recommended for supervision of atomizing medium pressure (air or steam) in an oil burner system.

Table 1. Models Available .

Model

Switching Action on Pressure Rise to

Setpoint

Operating RangesaMidscale Subtractive Differentiala

(Adjustable)Maximum Surge

Pressure

psi kg/cm2 kPa psi kg/cm2 kPa psi kg/cm2 kPaL404A spst, breaks

circuit0.5 to 5 0.035 to

0.353.4 to 35 Fixed (0.30 ± 0.15 psi maximum @

1.5 psi)8.5 0.6 59

2 to 15b .14 to 1.0 14 to 103 2 to 6 0.14 to 0.41 14 to 4 50 3.5 345

5 to 50 .35 to 3.5 34 to 345 4 to 12 .28 to 0.82 127 to 83 85 6.0 58610 to 150 .66 to 10.6 69 to 1034 8 to 16 0.56 to 1.10 55 to 110 225 15.8 1550

20 to 300c 1.4 to 21.0 138 to 2068 15 to 40 1.04 to 2.76 103 to 276 500 35.2 3445

L404Bf spst, makes circuit

2 to 15b .14 to 1.1 14 to 103 2 to 6 0.14 to 0.41 14 to 41 50 3.5 345

5 to 50 .35 to 3.5 24 to 345 4 to 12 0.28 to 0.82 27 to 83 85 6.0 58610 to 150 .66 to 10.6 69 to 1034 8 to 16 0.56 to 1.10 55 to 110 225 15.8 1550

20 to 300c 1.4 to 21.0 138 to 2068 15 to 40 1.04 to 2.76 103 to 276 500 35.2 3445

L404C spst, breaks circuit

2 to 15 .14 to 1.0 14 to 103 manual resetd(fixed, subtractive differential)

50 3.5 3455 to 50 .35 to 3.5 34 to 345 85 6.0 58610 to 150 .66 to 10.6 69 to 1034 225 15.8 1550

20 to 300c 1.4 to 21.0 138 to 2068 500 35.2 3445

L404D spst, makes circuit

2 to 15 .14 to 1.0 14 to 103 50 3.5 34510 to 150 .66 to 10 69 to 1068 225 15.8 1550

L404Fe spdt snap-acting switch, makes R1-W, breaks R2-B

2 to 15 .14 to 1.0 14 to 103 2 to 6 0.14 to 0.41 14 to 41 50 3.5 3455 to 50 .35 to 3.5 34 to 345 6 to 14 0.41 to 0.97 41 to 97 85 6.0 58610 to 150 .66 to 10 69 to 1034 10 to 22 0.69 to 15.2 60 to 152 225 15.8 1550

20 to300c 1.4 to 21.0 138 to 2068 20 to 50 1.4 to 3.5 138 to 345 500 35.2 3445

L604A spdt circuit makes R-W, breaks R-B

2-15b .14 to 1.0 14 to 103 2 to 6 0.14 to 0.41 14 to 41 25 1.8 172

5 to 50 .35 to 3.5 34 to 345 4 to 12 0.28 to 0.82 27 to 83 85 6.0 58610 to 150 .66 to 10 69 to 1034 8 to 16 0.56 to 1.10 55 to 110 225 15.8 1550

20 to 300c 1.4 to 21.0 138 to 2068 15 to 40 1.04 to 2.76 103 to 276 500 35.2 3445

L604L spdt circuit makes R-W, breaks R-B

2-15 .14 to 1.0 14 to 103 manual resetd (fixed, subtractive differential)

25 1.8 172

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

60-2150�12 4

Table 2. Switch Contact Rating (in Amperes at 50/60 Hz).

a L404F (snap-acting) does not have noninductive or dc ratings.b L604A and L have also been tested (and listed by Underwriters Laboratories Inc.) and breaking (not making) a load with a total

rating of 9.8A full load, plus 360 VA ignition, plus 250 VA pilot duty at 120 Vac.

Table 3. Conversion Table (psi to kPa).

MERCURY NOTICEIf this control is replacing a control that contains mercury in a sealed tube, do not place your old control in the trash. Dispose of properly. This control also contains mercury in a sealed tube. It must also be disposed of properly when it is replaced.

Contact your local waste management authority for instructions regarding recycling and the proper disposal of an old control.

Model Load 120 vac 240 Vac 120 Vdc 240 VdcL404 Full Load

Locked RotorNoninductivea

8.048.010.0

5.130.55.0

2.424.05.0

1.212.02.0

L604A,Lb Full LoadLocked RotorNoninductive

8.048.010.0

5.130.65.0

2.020.08.0

1.010.04.0

Operating Range Subtractive DifferentialEquivalent Equivalent

Scale-Plate (psi) kg/cm2 kPa Scale-Plate (psi) kg/cm2 kPa0 to 15 0 to 10 0 to 103 � � �2 to 15 0.14 to 1.0 14 to 103 1 to 6

2 to 60.77 to 40.14 to 0.4

7 to 4114 to 41

5 to 50 0.3 to 3.5 35 to 345 4 to 125 to 14

0.3 to 0.80.4 to 1.0

28 to 8341 to 97

5 to 150 0.3 to 10.3 34 to 1034 � � �10 to 150 0.7 to 10.3 69 to 1034 8 to 16

10 to 220.6 to 1.10.7 to 1.5

55 to 11069 to 152

20 to 360 1.4 to 20.7 138 to 2068 15 to 40 1.0 to 2.8 103 to 276138 to 345

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

5 60-2150�12

Fig. 1. Mounting dimensions of the L404A,B,C,D,F and L604A,L Pressuretrol® Controllers in in. (mm).

INSTALLATION

When Installing This Product�1. Read these instructions carefully. Failure to follow them

could damage the product or cause a hazardous condition.

2. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.

3. Installer must be a trained, experienced, flame safeguard control technician.

4. After installation is complete, check out product operation as provided in these instructions.

WARNINGElectrical Shock Hazard.Can cause severe injury, death or property damage.Disconnect the power supply before beginning installation to prevent electrical shock or possible equipment damage.

CAUTIONEquipment Damage Hazard.Improper use with a compressor can damage the controller.When using the controller with a compressor, install a dampening device (such as a needle valve, header, or surge tank) to dampen pulsations that can damage the controller or reduce its life.

IMPORTANT1. Locate the controller where the ambient temperature

will not exceed 150°F (66°C).2. Use pipe compound sparingly to avoid clogging the

hole in the pipe or diaphragm fitting.3. Do not tighten the controller by hand by holding the

case.4. Accurately level the controller for proper operation.

L404A-D,F; L604A,L

1/4-18 NPT

1

2

1

2

3

1

3

4-1/2 (114.3) (COVER)

4-11/32 (110.3) (CASE)

3/16 (4.8) X 21/64 (8.3)KNOCKOUT (2)

1-15/16 (49.2)

3-3/16 (81.0)

1-5/32(29.4)

2-1/8 (54.0)

2-3/4 (69.9)

1-61/64 (49.6)

1-13/16(46.0)

1-1/16(27.0)

13/16(20.6) 1/2 (12.7)

3-7/8(98.4)

7/8 (22.2) DIA.

1-1/2 (38.1)

1-3/16 (30.2)

1-1/16(27.0)

13/16(20.6)

4-31/32(126.2)

3-23/32(94.5)

RESET LEVER (ON MANUAL RESET MODELS ONLY.)

THIS DIMENSION IS 4-27/32 IN. (123.0 MM) ON L604 MODELS WITH A 2 TO 15 PSI (.14 TO 1.0 kg/cm2 (14 TO 103 kPa)) OPERATING RANGE, AND 5-3/4 IN. (146.A MM) ON L604 MODELS WITH A 20 TO 300 PSI (1.4 TO 20.7 kg/cm2 (138 TO 2068 kPa) OPERATING RANGE.

ONLY ON L604 MODELS WITH A 2 TO 15 PSI (.14 TO 1.0 kg/cm2 (14 TO 103 kPa)) OPERATING RANGE. M8933

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

60-2150�12 6

Location and MountingNOTE: For most accurate operation; add supplemental heat

to installations where the heat falls below -20°F (-29°C). Never locate the controller where the temperature falls below -35°F (-37°C), because mercury in the switch freezes at this temperature.

When used with steam boilers, always mount the controller above the water line in the boiler. A steam trap (siphon loop) must always be connected between the controller and the boiler (see Fig. 2) to prevent boiler scale and corrosive vapors from attacking the diaphragm. The loop on the steam trap must always be perpendicular to the face of the controller. If the loop is parallel to the controller, expansion or contraction of the loop tips the controller and causes inaccurate operation of the switch.

The controller can be mounted:

a. alongside the pressure gauge,b. in a fitting on the boiler provided by the

manufacturer,c. at a remote location in case of excessive vibration,d. in a special mounting on a low water cutoff.

Fig. 2. Right and wrong mounting of a steam trap (siphon loop), with approximate dimensions in in. (mm).

Make all pipe connections in accordance with approved standards. Use only a small amount of pipe compound to seal the connection joints. Excess pipe compound can clog the small hole in the fitting and prevent the controller from operating properly.

To avoid leaks and damage to the case, use a parallel jaw wrench on the controller hexagonal fitting. Do not tighten the controller by hand by holding the case.

LevelingA controller with a mercury switch must be accurately leveled for proper operation. It is level when the leveling indicator (see Fig. 11) hangs freely with its pointer directly over the index mark inside the back of the case. Level the controller by carefully bending the steam trap (siphon loop).

Mounting Alongside a Pressure GaugeTo mount the controller alongside a pressure gauge (Fig. 2), remove the gauge. In its place, install a steam trap (siphon loop) with a tee on top. Using elbows and pipe nipples, mount the controller and pressure gauge on the ends of the tee. Level the controller after installation.

Mounting on a BoilerIf it is not convenient to mount the controller alongside the pressure gauge, install steam trap (siphon loop) in the fitting provided by the boiler manufacturer. If there is no fitting, mount the steam trap at a location recommended by the boiler manufacturer. Screw the controller directly to the steam trap and level the controller.

Mounting at a Remote LocationIf there is excessive vibration at the boiler than can adversely affect the operation of the controller, mount the controller at a remote location. All piping from the boiler must be suitable and solidly mounted. The piping must be properly pitched to drain all condensation back to the boiler. A steam trap (siphon loop) must be mounted between the remote piping and the controller. Level the controller after installation.

Supervision of Atomizing Medium Pressure (Air or Steam)�L404BWhen air or steam is used as an atomizing medium in an oil burner system, authorities having jurisdiction (approval bodies and codes) often require a low limit to prevent opening the main oil valve until sufficient atomizing pressure is present, and to shut down the system when the atomizing pressure falls too low.

The L404B is recommended for this application. It makes a circuit when the pressure rises to the setpoint and breaks when the pressure falls to the setpoint minus the differential (Fig. 10).

Wiring

WARNINGElectrical Shock Hazard.Can cause severe injury, death or equipment damage.Disconnect the power supply before beginning wiring to prevent electrical shock or equipment damage.

4-1/2 TO 5-1/2(114.3 TO 139.7)

BOILER

14026STEAM TRAP(SIPHON LOOP)

TEE

PRESSUREGAUGEPRESSURE

CONTROLLER

M8934A

1

1 1/4 IN. BLACK IRON PIPE WITH 1/4 - 18 NPT EXTERNAL TRHEADS ON BOTH ENDS. BEND THE STEAM TRAP (SIPHON LOOP) TO LEVEL THE CONTROLLER.

CORRECT

BOILER

2-1/4 (57.2) DIA.

INCORRECT

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

7 60-2150�12

1. Assure all wiring complies with applicable electrical codes, ordinances and regulations. Use NEC Class 1 (line voltage) wiring.

2. For normal installation, use moisture-resistant No. 14 wire suitable for at lease 167°F (75°C) when you are using the controller with a flame safeguard primary control, or at least 194°F (90°C) when using it with a programming control.

3. For high temperature installations, use moisture-resistant No. 14 wire, selected for a temperature rating above the maximum operating temperature.

4. All models have a terminal block inside the cover (see Fig. 3 and 4) and a 7/8 in. (22 mm) hole in one side for 1/2 in. conduit, cable or wires. Remove the front cover by loosening the screw at the bottom of the main scale.

5. Refer to Fig. 5 through 9 for typical hookups. Follow the burner or boiler manufacturer wiring diagrams, if provided.

6. Make sure the loads do not exceed the Switch Contact Ratings in the Specifications section.

7. Replace the front cover when the wiring is completed.

Fig. 3. L404 terminal blocks and internal schematics.

Fig. 4. L604 terminal block and internal schematic.

Fig. 5. L404 used as a limit or as an operating controller.

Fig. 6. L404 with a low voltage relay.

Fig. 7. L404F, L604A (jumper installed) used as a high limit, with an alarm circuit.

RISE

BREAKS ON PRESSURE RISETO SETPOINT

RISERISE

RR R

W

W

W

B

B B

L404A,C L404B,D L404F(SNAP-ACTING)

MAKES ON PRESSURE RISETO SETPOINT

BREAKS R-B, MAKES R-W ONPRESSURE RISETO SETPOINT

M8941

RISE

B

W

L604A,LM8935B

R

M8936

L1 (HOT)

L2

2

1

1

2

PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

HIGH LIMIT�L404A OR C BREAKS WHEN PRESSURE RISES TO SETPOINT.LOW LIMIT�L404B BREAKS WHEN PRESSURE FALLS TO SETPOINTMINUS DIFFERENTIAL.OPERATING CONTROLLER�L404A BREAKS WHEN PRESSURE RISESTO SETPOINT, AND MAKES AGAIN WHEN PRESSURE FALLS TO SETPOINT MINUS DIFFERENTIAL.

L2

POWERSUPPLY

FLAMESAFEGUARDCONTROL,MOTOR, OROTHER LOAD

SPSTCONTROLLER

M8940

L1 (HOT)

L2

1

1

PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

24 VOLTTHERMOSTAT

LOW VOLTAGE RELAY L404

LOAD

THERM

POWER SUPPLY

1

2

M8937

L1 (HOT)

L2

2

1

1

2

PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

BREAKS R TO W AND MAKES R TO B WHEN PRESSURE FALLS TO SETPOINT MINUS DIFFERENTIAL.

L2

POWERSUPPLY

FLAMESAFEGUARDCONTROL,MOTOR, OROTHER LOAD

SPDTCONTROLLER(LOW LIMIT)

W

R

B

ALARM

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

60-2150�12 8

Fig. 8. L404F or L604A (with jumper installed) used as a low limit, with an alarm circuit.

Fig. 9. L404F or L604 with jumper installed, controlling an M6184 motor.

SETTING AND CHECKOUT

SettingIn all models, the differential is subtractive from the main scale set point. The upper operating point is determined by the main scale set point, while the lower operating point is determined by the main scale setting less the differential setting. The L404F and L604A (with jumper installed), L have spdt switching action. Operating points are shown in Fig. 10.

Fig. 10. L404 and L604 operating points.

Adjust the main scale set point for the desired operating pressure by turning the main scale adjusting screw (Fig. 11) on the top of the case until the main scale setting indicator is at the desired value. On an L404A,B,F with a 5 to 150 psi (.3 to 10.3 kg/cm2 [34 to 1034 kPa]) operating range, or an L604A, adjust the differential setting by turning the differential adjusting screw (Fig. 11) until the differential setting indicator is at the desired value. L404C,D and L604L are manual reset models: see the next paragraph. The scaleplates are marked psi and kg/cm2.

Trip-Free Manual Reset Feature (L404C,D and L604L only)The L404C breaks, the L404D makes, and the L604L makes R-W and breaks R-B when the pressure rises to the main scale setpoint. They will not automatically return to their former positions. To reset one of these controllers, wait until the pressure falls to the set point minus the differential (Fig. 10). Then depress the manual reset lever (Fig. 11) and release it. The controller will not be reset until you release the manual reset lever. This prevents the controller from becoming an automatic-reset device if the reset lever is stuck, held in, or tied down.

M8938

L1 (HOT)

L2

2

1

1

2

PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

BREAKS R TO B AND MAKES R TO W WHEN PRESSURE RISES TO SETPOINT.

L2

POWERSUPPLY

FLAMESAFEGUARDCONTROL,MOTOR, OROTHER LOAD

SPDTCONTROLLER(HIGH LIMIT)

W

R

B

ALARM

M8939

L1 (HOT)

L2

2

1

1

2

PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

BREAKS R TO B AND MAKES R TO W WHEN PRESSURE RISES TO SETPOINT.

POWERSUPPLY

SPDTCONTROLLER

W

R

B

W1

R1

B1

L1

L2M644B

LINE VOLTAGETWO-POSITION MOTOR

CLOSED(LOW FIRE)

OPEN(HIGH FIRE)

WHITE

RED

BLUE

BLACK

BLACK

MAIN SCALE SETPOINT(SWITCH BREAKS)

SUBTRACTIVEDIFFERENTIAL

DIFFERENTIAL SETTING(SWITCH MAKES)

PRESSURERISE

L404A,C

1

MAIN SCALE SETPOINT(SWITCH MAKES)

SUBTRACTIVEDIFFERENTIAL

DIFFERENTIAL SETTING(SWITCH BREAKS)

PRESSURERISE

L404B,D

1

MAIN SCALE SETPOINT(BREAKS R-B, MAKES R-W)

SUBTRACTIVEDIFFERENTIAL

DIFFERENTIAL SETTING(MAKES R-B, BREAKS R-W)

PRESSURERISE

L404F;L604L

1

MAIN SCALE SETPOINT(MAKES R1-W, BREAKS R2-B)

SUBTRACTIVEDIFFERENTIAL

DIFFERENTIAL SETTING(BREAKS R1-W, MAKES R2-B)

PRESSURERISE

L604A

1 L404C,D AND L604L MANUAL RESET MODELS HAVE A SMALL, FIXEDDIFFERENTIAL. THEY CAN BE MANUALLY RESET WHEN THE PRESSUREFALLS TO THE MAIN SCALE SETPOINT MINUS THE DIFFERENTIAL.

M8942

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

9 60-2150�12

Fig. 11. Setting a Pressuretrol® Controller.

CheckoutAfter the controller has is installed, wired, and set, test it with the system in operation. First allow the system to stabilize. Then observe the operation of the controller while raising and lowering its setpoint. Pressure should increase when the setpoint is raised and decrease when the set point is lowered.

Also check the make and break points of the controller. If they do not agree with a separate, accurately calibrated pressure gauge, a slight adjustment of the scaleplate(s) may be necessary.

Use accurate pressure testing equipment when checking out the controller. Do not rely on inexpensive gauges. The controllers are carefully calibrated at the factory.

Boiler InstallationIf the controller is being used on a boiler installation, test it as follows:

1. Note the boiler pressure by checking the boiler pressure gauge. (To perform this test properly, the boiler should have a pressure reading near the middle of the controllerÕs main scale range.)

2. Turn the main scale adjusting screw (Fig. 11) until the main scale setting indicator on the controller corresponds to the boiler pressure gauge reading.

3. The L404A or C should break the control circuit(s) automatically when the boiler pressure gauge reading equals or slightly exceeds the controller setting.

4. The L404B or D should make the circuit under the same circumstances.

5. The L404F; L604L should make the R-W circuit and break the R-B circuit under the same circumstances.

6. The L604A should make the R1-W circuit and break the R2-B circuit under the same circumstances.

7. If the controller is operating properly, turn the main scale adjusting screw (Fig. 11) until the main scale setting indicator is at the desired set point.

If a Controller Seems to Operate ImproperlyIf the controller is suspected of operating improperly, it may be further checked as follows (Fig. 12):

1. Disconnect all power to the controller, loosen the cover screw, and remove the cover.

2. Disconnect the wires from the controller.3. Connect an ohmmeter between the switch terminals.4. Lower the set point of the controller (simulating a

pressure increase) through a range greater than the differential. The switch should either make or break, depending on the model of the controller. (An L404A or C should break, an L404B or D should make, an L404F; L604L should break R-B and make R-W, and an L604A should break R2-B and make R1-W.) If it makes, the ohmmeter reads zero; if it breaks, the ohmmeter reads infinity.

5. Raise the set point of the controller (simulating a pressure decrease) through a range greater than the differential. The switch should break or make, just the opposite of its action in step 4 (except for the L404C,D and L604L manual reset models).

NOTE: An approximation of the differential can be made by observing the change in set point required for a resistance change from zero to infinity.

6. If the controller operates improperly, replace it.7. When the controller is operating properly, reconnect the

wires to the terminal block, replace the cover and tighten the cover screw, and reconnect the power.

CAUTIONEquipment Damage Hazard.Improper operation can damage the equipment.Do not put the system into service until you have satisfactorily completed all applicable tests described in this Checkout section, in the Checkout section of the applicable instructions for the flame safeguard control, and any others required by the burner and boiler manufacturers.

MERCURY SWITCH

DIFF. MAIN

PSI

12108642 .1

.3

.5

.7

.8

.6

.4

.2

0.51

20

10

30

40

503.53

2.52

1.5

0

DIAPHRAGMASSEMBLY LEVELING

INDICATOR

POINTER

INDEX MARK

MANUALRESET LEVERMAIN SCALE

ADJUSTINGSCREW

DIFFERENTIALADJUSTINGSCREW

SCALEPLATES

DIFFERENTIAL SETTINGINDICATOR

MAIN SCALESETTINGINDICATOR

ADJUSTABLE DIFFERENTIAL ON THE L404A,B,F; L404L WITH A 5 TO150 PSI (0.34 TO 10.3 kg/cm2 [34 TO 134 kPa] OPERATING RANGE; AND L604A MODELS ONLY.

TRIP-FREE MANUAL RESET LEVER ON THE L404C,D AND L604L MODELS ONLY. M8943

1

2

1

2

L404A-D, F; L604A,L PRESSURETROL® CONTROLLERS

60-2150�12 10

Fig. 12. Checking controller operation using an ohmmeter.

SERVICE INFORMATION

CalibrationThe controller was carefully calibrated during manufacturing and should not require recalibration. Most calibration errors are caused by improper leveling. The controller should be level when the pointer on the leveling indicator is directly over the index mark (Fig. 11). In some cases, the leveling indicator may not be accurate enough. The pointer may be over the index mark, but the controller still may not be operating within the tolerance of its scale setting. In this case, carefully bend the steam trap (siphon loop) until the controller switches properly.

MaintenanceThe cover of the controller should be in place at all times to protect the internal components from dirt, dust, and physical damage. Routine maintenance should consist of occasional inspection and blowing or brushing away any accumulated dirt and dust. To ensure proper functioning of the controller at all times, perform an operational check of the entire system during routine maintenance checks.

M8944A

INPUT OUTPUT

ZEROADJ

0

W

R

B

SETPOINTDECREASE

ZERO OHMS(INFINITY WHEN R-B BREAKS)

OHMMETER

1 AN L604 IS SHOWN. AN L404F OPERATES SIMILARLY (SPDT SWITCHING). AN L404A, B, C OR D HAS ONLY TWO TERMINALS (SPST SWITCHING); AN L404A R C BREAKS AND L404B OR D MAKES WHEN THE SETPOINT IS DECREASED FAR ENOUGH.

1

11 60-2150�12

60-2150�12 G.R. Rev. 09-03 www.honeywell.com

Automation and Control SolutionsHoneywell International Inc. Honeywell Limited-Honeywell Limitée1985 Douglas Drive North 35 Dynamic DriveGolden Valley, MN 55422 Scarborough, Ontario

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